Some Ideas:
-The Snake Girl says she has 2 Dicks, but she actually doesn´t. Why not make that a Feature? A Double Eggplant or something that gives you two Dicks at once, with special Poses associated (IE Double D Anal, Anal+Vaginal etc.)
-Various UI Changes, specifically the ones relating to the Xray on Fuck Minigames. Some for the Throat for example would be nice, as well as updated Sprites for the various different Dick Types (A lot just look the same)
-Gangbanging! 2 Options that would be great are 1. Characters joining in on chosen Poses when they´re at high Heat and 2. A Double Cherry Item that duplicates the Dominant Character. Maybe you could even use it on yourself to literally "go fuck yourself"
-Some Sort of Use for Babies. Of course you could create a massive Character Creation Thingy that creates Hybrids of the Parents´ Species but that sounds like a ton of work, so I´ll leave the choice to you; just know any Use at all is what I´m requesting
-This one may break the concept of the Game, but some sort of Scene Studio Mode would be cool. You could choose 2 Characters, their Customizations and the Pose right from a Menu rather than the more "immersive" Version used ingame. Just an idea though, the current way is fine